It is desirable to reduce range ambiguities in treatment planning for making full use of the major advantage of heavy-ion radiotherapy, that is, good dose localization. A range verification system using positron emitting beams has been developed to verify the ranges in patients directly. The performance of the system was evaluated in beam experiments to confirm the designed properties. It was shown that a 10C beam could be used as a probing beam for range verification when measuring beam properties. Parametric measurements indicated the beam size and the momentum acceptance and the target volume did not influence range verification significantly. It was found that the range could be measured within an analysis uncertainty of +/-0.3 mm under the condition of 2.7 x 10(5) particle irradiation, corresponding to a peak dose of 96 mGyE (gray-equivalent dose), in a 150 mm diameter spherical polymethyl methacrylate phantom which simulated a human head.
The presence of the magnetic quadrupole term in addition to the electric dipole one in the multipole expansion of the radiation field is reflected in the angular distribution of the x-ray transition. To extend the previous works we studied the angular distribution of different L, x-ray liner of Ba, Sm and Er experimentally for proton impact at 0.23.0.28 and 0.35 MeV bombarding energies respectively, using a Si(Li) detector. The anisotropy parameter ratios of the LI and L a transitions were found to be 5.2i2.8, 5.5e0.7 and 6.93,l.S. Angular distributions of Tb L-shell x-rays were also measured by a high resolution crystal spectrometer for 0.556 MeVamu-' nitrogen ions, P value of 3.5e2.5 was obtained far the anisotropy parameter ratio. There ratios deviate significantly from the theoretical ones. The obtained ratios were in good accord with the same quantities derived from the earlier Ka,~Langularcorrelatian parameters. The effect ofthe magnetic quadrupole mining on the determination of the alignment parameter i s demonstrated for the case of the L, subshell of gold.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.